The present invention relates to a printing apparatus such as a laser printer for performing printing by feeding, one by one, a piece of paper from a paper receiving portion to a printing mechanism by means of a paper feeding mechanism on the basis of a data information fed from a host computer.
Conventionally, in such a printing apparatus, a piece of paper on a delivery path is fed at a constant speed, and the information may be printed in synchronism between the paper feeding speed and a writing timing of information for the printing portion. In particular, in the case where the delivery path from the paper accommodating portion to the printing portion is long, if a subsequent piece of paper is fed from the paper accommodating portion to the printing portion after a printing operation, the waiting time for the printing would be long so that the printing speed of the printing apparatus as a whole would be low. Accordingly, in order to solve this problem, there has been provided a printing apparatus in which the next or subsequent paper is once fed from the paper accommodating portion to a print waiting position during the printing operation in the printing portion to be in preparation for the next printing operation. In some cases, even if a constant time has lapsed and a next printing command is not effected, the once fed paper is discharged in a constant period of time (see Japanese Patent Unexamined Publication No. 56-85762).
However, if the paper is held at the print waiting position for a long period of time, the paper would be deformed due to the shape of the delivery path which is generally curved to make the printing apparatus compact and the pressure imposed by the feeding rollers, so that a paper jamming would be likely to be generated. Also, in the case of the conventional system in which the paper is discharged in a constant period of time, the paper would be deformed due to the delivery of the paper along the delivery path. In this case, when the deformed paper is used again for the printing, the paper would be likely to be jammed during the printing period, disadvantageously.